Cathode-ray tube sealing apparatus



Jan. 1, 1952 w, MELHER ETAL 2,580,450

I CATHODE-RAY TUBE SEALING APPARATUS Filed Dec. 5, 1950 2 SHEETSSHEET 1 GAS g a? R 24 S J 1 RESILIENT 2| I I 2 RESILIENT SUPPORTING I 2| SUPPORTING ARM 30 I III4 I 3| 3| I 3| I [/I 39 ARM I 2 38 i F 1 1 3 9' 1 38G I I o I. z I

GAS 35 MANIFOLD 35 INVENTORS WALTER P MELCHER HARRY H VOELZ THE/R A 7' TOR/V5 Y Jan. 1, 1952 W. P. MELCHER ETAL CATHODE-RAY TUBE SEALING APPARATUS Filed Dec. 5, 1950 2 SHEETSSHEET 2 WALTER P MELCHER HARRY H. VOELZ THE/l? ATTORNEY Patented Jan. 1, 1952 UNITED STATES PATENT OFFICE Walter P. Melcher and Ha IlL, assignors to The R I corporation of Illinois Application December 5, 1950, Serial No. 199,239-

'This invention relates to improved apparatus for the fabrication of cathode-ray tubes having an envelope comprising a neck portion of vitreous material such as glass or the like, a hollow flaredor conical portion which may be of metal, and a'window or viewing plate of glass or similar transparent material. More particularly, this invention' is directed to improved apparatus for sealing the glass viewing plate to the hollow conical "portion of a cathode-ray tube envelope in which these portions have a rectangular or other non-circular cross section.

In cathode-ray tubes of the metallic type, the conical portion of the envelope is usually provided with a flange or lip at one end in which the glass window is fitted for sealing purposes. To obtain a satisfactory seal it is preferable that the cone be held with its axis in a vertical position and the window be placed on its upper end in contact with the flange. Gas burners may then be directed to the underside of the flange and the assembly rotated about its axis for uniformity of heating. The heat from the burners causes the glass of the window in contact with the flange to soften and settle onto the flange, sealing the window to the conical portion.

Heretofore in the art it has been usual that cathode-ray tube envelopes be composed of a tubular neck portion, a hollow conical portion of circular section, and a circular viewing or face plate. As previously stated, the face plate may be sealed to the conical portion by placing the cone in a suitable apparatus with its large end upward and the face plate resting thereon. An array of heating elements may be positioned to surround the conical portion and directed to its upper'end. Relative rotation may then be imparted between the burners and the conical portion of uniform heating.

The advent of rectangular-screen cathode-ray tubes for use in television receivers has presented a serious sealing problem. That is, it hasbecome necessary to provide apparatus whereby heat may be applied uniformly tween the cone and face plate portions of a cathode-ray tube envelope when the sections of these portions are not circular. As long as these sections are circular, uniform heating may be obtained simply by arranging the heating elements in an array surrounding the cone and 'efiecting relative rotation between the cone and the heating elements, as described above.

The present invention provides improved apparatus for effecting 'an eflicient seal between theviewing plate and conical portion of a cathto the sealing surface be-' 3 Claims. (Cl. 491) rry H. Voelz, Chicago, auland Corporation, a

ode-ray tube envelope when these portions have a rectangular or other non-circular section; and it-renders feasible the production of rectangular-screen cathode-ray tubes, particularly of the metallic type. The apparatus comprises a supporting means having a structure mounted therei on for supporting the hollow generally conical portion of a cathode-ray tube which maybe composed of metal, and which may have a flanged end of a rectangular or other non-circular cross-sectional configuration. The conical portion is supported in the aforementioned structure with its flanged end upward and with the viewing plate resting thereon. A cam having a contour corresponding to the peripheral configuration of the flanged end of the cone is mounted on the supporting structure in coaxial relation with the cone in a plane parallel to the plane of the flange, and a continuous chain is supported by and encircles the cam. A plurality of gas burners are mounted on the chain extending upwardly and directed towards the underside of the flanged end of the cone. Finally, the apparatus includes a driving means for imparting relative rotational motion between the cam and chain so that the burners may follow the contour of the flanged end of the cone for uniform heating of the flange ing plate of a cathode-ray tube to a hollow, generally'conical, metallic portion having a flanged end, especially when the viewing plate and flange have a rectangular or other non-circular configuration.

The features of this invention which are believed to be new are set forthwith particularity in the appended claims. The invention itself, however, together with further objects and advantages thereof may best be understood by reference to the following description when taken in conjunction with the accompanying drawings, in which:

Figure 1 shows one embodiment of the improved sealing apparatus of the invention, supporting various portions of a cathode-ray tube envelope which are to be sealed together,

Figure 2 shows -a view of the apparatus of Figure 1 taken along the lines 2--2, but with the envelope portions removed for purposes of clarity,

Figure 3 shows'a view of the apparatus taken 1 lar viewing plate.

along the lines 3-3 of Figure 2, but with some components of the apparatus omitted to simplify this view, and,

Figure 4 represents a burner-supporting bracket as viewed along the lines 4-4 of Figure 1.

The apparatus of Figure 1 includes a supporting means or table, ID. having an. upwardly-- extending tubular; driving member, ll rotatably mounted thereon. An electrical motor is mounted on a shelf 16 of the supporting table and is: mechanically coupled by abelt drive, I! to a, driving wheel l4 which is affixed to tubular driv ing member H.

Driving member I I has a turn-table-IB- secured to its upper end so that energization of motor I6 causes the turn-table to rotate. Turn-table I8 supports a plurality of upwardly-extending brackets is which, in turn, support a cam assembly shown more clearly in Figures 2 and 3. The cam assembly.- has a central, aperture. surrounded by brackets 2 I which serveasa support ing means forthe cone 22- of they cathode-ray tube envelope. It will. be assumedthatcone. 22 has afiange surface 24 of rectangular. cross-.- sectionat its large end for receiving arectangu- I Moreover, it ,willbe assumed that the small endof .the cone has been. previous: ly sealed to a. vitreousneck portion ,.23; The. brackets 2| engage the cone so thatthecone and the cam assemblyrotate inunison as turnrtable l8 isrotated. Cam assembly 20 is constructedto have a contour corresponding to the rectangular configuration of flanged-end 24 of cone22, and

thecone issupported with theplane ofits flanged end parallel .to the plane of cam 20 and. incoaxial. relation {therewith A continuouschain 29 is. supported by, cam assembly 20 and encircles the .peripheryof the; cam. The chain is of usualwell-known construe.- tion andis composedof variouslinks and inter connecting transverse pins, the pins additionally acting ina manner to be described-as rollersene gaging' a surface ofcam assemblyZD. The upper: links or chain 29-,are replaced bybrackets-30 shown in Figure A, and these ,brackets support an array .of upwardly-extending burners 3 I die rected to' flanged end,;24 of cone 22...Burners.,3l are coupled toa gas, manifold., 32 by means of rubbertubes 33. Apairof upwardly extending rods 34 is mounted on table, It] and the-gas mani-. fold is supported on these rods. by means of collarse 35 secured theretoby screws 36. Rods 34 also support apair of resilient supporting arms 38, V39.

which are mechanically coupled to the chain-to.

prevent rotational motion thereof as the cam.as-..-

sembly. is rotated Thesemresilient supporting.

arms are conneq ed to rotatable col1ars..38a,. 39a on rods 34,'the rotatable collars being supported.

on the rods by secured collars 381),.392). ,The suppo'rtingarms are urged ,againstchain, 29. by tens. sion springs 40, 4| (Figure. ,2) the tension springs being connected to the arms and to, upwardly, extending strips 42; 43 fixed to the gas manifold.

As ,shown. in the section, of Figure3, cam ase sembly 20 ,may comprise a pair .of, plates, 44, .45 spaced apart by tubular spacing membersMiLfl and held together by screws 48,, 49. The .pe-

ripheries of plates 44, 45 engage the roller pin.

portions 50,5! of chain 29, andlform what may. 7o

be termed tracks for the chain. .Moreover the. cam assembly may includea bottom p1ate..45a

spaced fromplate 45 by a plate 45b,'the bottom plate acting as a support for thev chain. As shown.

cured to brackets 30 by means of a threaded portion 52. The threaded portion may be screwed into a tapped hole in each bracket, or may be secured to the bracket by means of a nut on the threaded portion.

The apparatus also includes an air tube 25 mounted coaxially within tubular driving member I.I- in frictional engagement-therewith and extending. upwardly through turn-table l8 into the neck portion 23 of the cathode-ray tube envelope. Air tube 25 projects through a rubber air, seal.2.6 and. hasa small aperture 21 formed thereinwhich'a'cts'as a bleeder. Air is introduced into the-air-itube-through a rotary air seal 28 of well-known: construction.

Tosperform thesealing operation, the flanged cone, 22. and. neck. portion 23 of a cathode-ray tube envelope are placed in the aperture of cam assemblydfl and supported by brackets 2| so that the plane of the flanged end 24 of the cone is parallel totheplanevofthe cam assembly;- Face plate 31 isthen placed on thezflangedi end. Rub-i ber air seal 26isinserted into the neck portion as;shown,,and. electrical motori5 is energizedto ,rotate turnetable. I8. Rotation of. the turntable..causes.cam assembly 28 and cone -22-htorotate-,in unison; Rotation of chain 29,ispre vented. by resilient arms*38;, 39, {the ichain bei'ngs loosely supported by, the cam so. that rotationof the camcausesethe configuration of the chainto. follow the'contour, of the-rotating camwhich, in turn, causes the burners-supported by the 'chain to follow thecontour of the .flanged end of the cones" Burners -.3I are .ignited to heat'the'under sidezof-the flange-..24- and-fbring the flange to the sealing temperature Air under pressure is introduced through air 'tube25 into theinterionofathe envelope assemblyto prevent :the edge of. viewing; plate 3'! from; sagging. duringv the sealing ;;operation. Aperture :21 in' thevair" tub-e:"a,11OWS" 801118 ofthisair .to escapeand avoids excessive pressure i in the interior of the cathode-rayiztuber- It is sometimes desirable to heatxviewingplateri- 31 priorito the -sealing;process. so that cracking;

will be prevented. This is accomplished-bymeans' tion. of these elements, theburners are caused-tor follow their contour and provide uniiormmeat ing around-their. periphery so thata satisfactory seaLImayv be obtained Moreover; when s05. de r r sired the apparatus is readily:adaptableior seal -z ing the viewingplatehto thecone of acathode ray tube havinga-circular section,it beingimere ly necessary to provide .cam 20 with aacorre spending circular configuration.

While a .particula'nembodimentof the :inven tion has, been .shownand described, modifica-ew tions may be madeflandit .is intended iII' thG appended claims to :cover all such. modifications asmay ,fall within.v the true. spirit. and: scope 5015;?-

the invention.

We claim s.

I 1..Apparatus for sealingiaiviewing plate por 111171115 fi u e each f the burners 3|. m y b 56.- 15. tion' ofia cathqderl'aymtubfltd' alhonbw generally-T conical. portion having a flanged end comprising: a supporting means; a structure mounted on said supporting means for supporting said conical portion with said flanged end upward and with said viewing plate resting thereon; a care member having a contour corresponding; to the peripheral configuration of said flan ed end mounted. on said structure in a plane parallel to the plane of said flanged end and in coaxial rela tion with said conical portion; a continuous chain encircling said cam member; a plurality of heating elements supported by said chain and rected towards said flanged end of said conical portion; and driving means for imparting relative rotational motion between said and chain.

2. Apparatus for sealing a viewing plate por-- tion of a cathode-ray tube to a hollow generally conical metallic portion having a flanged end comprising: a supporting means; a structure mounted on said supporting means for supporting said metallic portion with said flanged end upward and with said viewing plate resting thereon; a cam member having a contour corresponding to the peripheral configuration of said flanged end mounted on said structure in a plane parallel to the plane of said flanged end and in coaxial relation with said conical portion; a continuous chain supported by said cam and encircling the periphery thereof; resilient support ing means mechanically coupled to said chain for preventing rotational motion of said chain; a plurality of heating elements supported by said chain around the periphery of said cam and directed towards said flanged end of said conical portion; and driving means coupled to said supporting structure for imparting rotational motion to said cam.

3. Apparatus for sealing a viewing plate portion of a cathode-ray tube to a hollow generally conical metallic portion having a flanged end comprising: a supporting means; a structure mounted on said supporting means for supporting said metallic portion with said flanged end upward and with said viewing plate resting thereon; a cam member having a peripheral configuration corresponding to the peripheral configuration of said flanged end mounted on said supporting structure in a plane parallel to the plane of said flanged end and in coaxial relation with said conicai portion; a continuous chain supported by said cam and encircling the periphcry thereof; a pair of resilient supporting arms mechanically coupled to said chain for preventing rotational motion of said chain; a plurality 01f upwardly-extending gas burners supported by said chain around the periphery of said cam and directed toward said flanged end of said conical portion; and driving means coupled to said supporting structure for imparting rotational motion to said cam.

WALTER P. MELCHER. HARRY H. VOELZ.

No references cited. 

